UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

RESEARCH TRIANGLE PARK, NC 27711 

OCT 2 2007 

MEMORANDUM 

OFFICE OF 

AIR QUALITY PLANNING 

AND STANDARDS 

SUBJECT: Guidance on SIP Elements Required Under Sections 1 lO(a)(l) and 

(2) for the 1997 8-hour Ozone and PM2.s National Ambient Air 

Quality Standards 

FROM: rirrwilliam T. Harnett, Direct_;/ · (})~ U Air Quality Policy Divisio~f{t 

TO: Air Division Directors, Regions I-X 

The purpose of this memorandum is to provide guidance on the 

"infrastructure" elements for State Implementation Plans (SIPs) required under 

section l lO(a)(l) and (2) of the Clean Air Act (CAA) for the 1997 8-hour ozone 

and fine particulate matter (PM2.5) national ambient air quality standards 

(NAAQS). Attachment A to this memo provides a list of the basic elements that 

States must include in their SIPs. To the extent that existing SIPs for ozone and 

particulate matter already meet these requirements, States need only certify that 

fact to the Environmental Protection Agency (EPA). To the extent that existing 

SIPs for ozone and particulate matter fail to address any of these requirements for 

purposes of the 1997 8-hour ozone or PM2.s NAAQS, States need to make timely 

SIP submissions to EPA to address these requirements. We anticipate that States 

will already have approved SIPs in place for ozone that meet the basic 

requirements of sections 11 O(a)(l) and (2). For PM2.5, however, we anticipate 

that many States may need to make SIP revisions to ensure that their existing SIPs 

for prior particulate matter NAAQS are revised to include the new particle size 

indicator. 

Background 

On July 18, 1997, the EPA promulgated new and revised NAAQS for 

ozone and particulate matter. For ozone, EPA revised the NAAQS to provide an 

8-hour averaging period (versus a 1-hour averaging period for the pre-existing 

NAAQS), and set the level of the standard at 0.08 ppm (versus 0.12 ppm for the 

pre-existing NAAQS). For PM, EPA promulgated a new 24-hour and a new 

Internet Address (URL)• http://www.epa.gov 

Recycled/Recyclable •Printed wtth Vegetable Oil Based Inks on Recycled Paper (Minimum 25% Postconsumer) 
annual NAAQS for PM2.5 (particles with an aerodynamic diameter less than or 

equal to a nominal 2.5 micrometers). 1 

Under sections l lO(a)(l) and (2) of the CAA, all States are required to 

submit plans to provide for the implementation, maintenance, and enforcement of 

the 8-hour ozone and PM2.5 standards. Sections l lO(a)(l) and (2) require States 

to address basic SIP requirements, including emissions inventories, monitoring, 

and modeling to assure attainment and maintenance of the standards. By statute, 

SIPs meeting the requirements of sections 11 O(a)(l) and (2) are to be submitted 

by States within 3 years after promulgation of a new or revised standard. This 

being the case, States were required to submit such SIPs for the 1997 standards to 

EPA no later than July 2000. However, intervening litigation over the 1997 

8-hour ozone and PM2.5 NAAQS, created uncertainty about how to proceed and, 

to date, States have not submitted SIPs to meet the basic or infrastructure 

requirements enumerated in sections 1 lO(a)(l) and (2). 

In March of2004, Earth Justice initiated a lawsuit against EPA for failure 

to take action against States that had not made SIP submissions to meet the 

requirements of sections 11 O(a)(l) and (2), i.e., failure to make a "finding of 

failure to submit." On March 10, 2005, EPA entered into a Consent Decree with 

Earth Justice that obligates EPA to make official findings whether States have 

made required SIP submissions by dates certain. The Consent Decree obligates 

EPA to determine whether States have made SIP submissions required to meet 

CAA section 11 O(a)(2)(D)(i) relating to interstate transport by no later than 

March 15, 2005. The Consent Decree also obligates EPA to make a 

determination whether States have made submissions necessary to meet the 

remaining l lO(a)(l) and (2) requirements by December 15, 2007, for the 8-hour 

ozone NAAQS, and by October 5, 2008, for the PM2 .. s NAAQS.2 It should be 

noted that the latter determinations pertain only to whether the submissions are 

complete, pursuant to section l lO(k)(l )(A), and do not constitute EPA approval 

or disapproval of such submissions. In addition, the determinations required by 

the Consent Decree explicitly exclude any determinations regarding: (i) 

1 More recently, on December 18, 2006, EPA again revised the standards for particulate matter, 

tightening the 24-hour PM2.

5 standard from 65 micrograms per cubic meter (μg/m3

) to 35 μg/m, 3 

and retaining the current annual fine particle standard at 15 μg/m3

. EPA also decided to retain the 

existing 24-hour PM10 standard of 150 μg/m3 and to revoke the annual PM10. This guidance 

document applies only to the SIP submission requirements for the 1997 8-hour Ozone and PM2.5 

NAAQS. EPA will address SIP requirements for the 2006 NAAQS separately, although the 

Agency notes that the statutory requirements for SIPs for new or revised NAAQS are comparable. 2

The dates specified in the Consent Decree reflect the anticipated dates for submission of 

nonattainment area SIPs for each NAAQS, plus six months for EPA evaluation. EPA presumed 

that States would make SIP submissions meeting the basic requirements of sections 1 lO(a)(l) and 

(2) for each NAAQS contemporaneously with, or not later than, SIPs meeting the nonattainment 

area plan requirements. EPA notes that recent decisions by the U.S. Court of Appeals for the 

District of Columbia concerning the implementation rule for the 8-hour Ozone NAAQS have 

affected certain nonattainment area SIP requirements. These judicial decisions do not, however, 

affect States' obligations under the CAA or EPA's obligations under the Consent Decree 

concerning the infrastructure SIP requirements of sections 1 IO(a)(l) and (2). 

2 
submissions required by section l 10(a)(2)(C) to the extent that subsection pertains 

to a nonattainment area new source permit program in part D Title I of the CAA; 

and (ii) submissions required by section l 10(a)(2)(I) for Part D Title I 

nonattainment area plans. 

In accordance with the Consent Decree, EPA has already published a 

finding that all States had failed to submit new SIPs addressing interstate transport 

for the 8-hour ozone and PM2.5 NAAQS, as required by section 11 O(a)(2)(D)(i) of 

the CAA (70 FR 21147, April 25, 2005). That finding initiated a 2-year deadline 

for the promulgation of a Federal Implementation Plan (FIP) by EPA for each 

such State unless, prior to that time, each State makes a submission to meet the 

requirements of Section 11 O(a)(2)(D)(i) and EPA approves such submission. On 

May 12, 2005, EPA published the Clean Air Interstate Rule (CAIR) which 

identifies the degree to which emissions of S02 and NOx in certain States 

significantly contribute to nonattainment of, or interfere with maintenance of, the 

1997 8-hour ozone and PM2.5 NAAQS in downwind States, and the reductions 

that must be achieved in those States to eliminate such contributions. 

On August 15, 2006, EPA issued guidance entitled "Guidance for State 

Implementation Plan (SIP) Submissions to Meet Current Outstanding Obligations 

Under Section l 10(a)(2)(D)(i) for the 8-hour Ozone and PM2.s National Ambient 

Air Quality Standards." The section l 10(a)(2)(D)(i) guidance indicates that 

States within the CAIR region can satisfy 110(a)(2)(D) by satisfying the 

requirements of the CAIR, and addresses what other States that are outside of the 

CAIR region should consider doing to meet the "significant contribution" and 

"interfere with maintenance" requirements of section 11 O(a)(2)(D)(i) for the 1997 

standards. The section l 10(a)(2)(D)(i) guidance also addresses what all States 

(whether inside or outside of the CAIR region) should consider in making SIP 

submissions to meet the "prevention of significant deterioration" and "protect 

visibility" requirements of section 11 O(a)(2)(D)(i). The SIP submissions 

addressed by the section 11 O(a)(2)(D)(i) guidance are those that are necessary to 

rectify the finding of failure to submit that EPA has already issued for all States 

for section 110( a)(2)(D)(i). 

The guidance contained in this memorandum is intended as a reminder 

that States must have SIPs for the 1997 8-hour ozone and PM2.s NAAQS that 

meet all of the requirements of sections l lO(a)(l) and (2). Pursuant to the 

Consent Decree, EPA has an obligation to take action to determine whether States 

have made such submissions by the dates noted above. Because States should 

currently be in the process of submitting nonattainment SIPs for the 8-hour ozone 

standard and working on nonattainment area SIPs for the PM2.s standard, we want 

to alert them to be sure that their SIPs also meet the basic requirements of sections 

1 lO(a)(l) and (2). 

3 
Guidance 

The EPA believes that the currently-approved section 110 SIPs for ozone 

may already be adequate in most cases to implement the 8-hour ozone NAAQS. 

Many of the required section 1 IO(a)(l) and (2) SIP elements relate to the general 

information and authorities that constitute the "infrastructure" of the ozone air 

quality management program, and these have been in place since the initial SIPs 

were submitted in response to the 1970 Clean Air Act. For particulate matter, 

however, EPA believes that some States may need to adopt language specific to 

the PM2.s NAAQS to ensure that they have adequate SIP provisions to implement 

the PM2.5 NAAQS, e.g., existing State laws may refer to PM10 specifically or to 

particulate matter more generally, rather than to PM2.s. We believe that with one 

exception, the infrastructure requirements of sections 110( a)(l) and (2) are 

relatively self explanatory, and past experience with SIPs for other NAAQS 

should enable States to meet these requirements with assistance from EPA 

Regions. The one exception is section 11 O(a)(2)(G) relating to emergency 

episodes, for which EPA intends to take additional regulatory action to provide 

necessary numerical limits and concentration levels for emergency episode action 

plans for PM2.s. 

States should review and revise, as appropriate, their existing ozone and 

particulate matter SIPs to ensure that they are adequate to address the 8-hour 

ozone and PM2.5 NAAQS. If a State determines that its existing SIP is adequate, 

then the State needs to certify, via a letter to the Agency from the Governor or 

his/her designee, that the existing SIPs contain provisions that address the 

requirements for the 8-hour ozone and PM2.s NAAQS. If a State determines that 

its existing ozone or particulate matter SIPs are inadequate, however, then the 

State needs to submit a SIP revision to make the appropriate changes. 

With respect to PM2.s, States may find it more advantageous to revise the 

language in their SIPs to identify "particulate matter" as the pollutant being 

implemented and define the size fractions as "those that EPA has currently set for 

the NAAQS" to the extent such an approach would be authorized by State law. 

This will ensure that the provisions remain adequate in the event that future 

changes occur to the particulate matter standards. States could also specify both 

PM10 and PM2.5 as the size fractions if a State prefers to be more specific. 

As an aid to the States in addressing the PM2.s related requirements of 

Section 1 IO(a)(2)(G) pertaining to emergency episode provisions, EPA intends to 

take action to revise 40 CFR, Part 51, subpart H (sections 51.150). The rule 

changes will establish the priority classifications which determine the emergency 

episode plan requirements for each area and establish a significant harm level 

(SHL) for PM2.5. Until these changes are final, EPA recommends that States rely 

on relevant information contained in upcoming EPA rule proposals or other EPAissued interim guidance to satisfy the section 1 IO(a)(2)(G) requirements for 

PM2.5• After EPA issues final rules, EPA will work with States to revise SIP 

4 
submissions that were based on interim information, as appropriate. States may 

wish to take advantage of the parallel processing mechanism for making their 

section 110(a)(2)(G) submittal in the interim while EPA completes rulemakings 

on the SHL and the emergency episode plan requirements under 40 CFR 51.150. 

The SHL for the 8-hour ozone NAAQS will remain unchanged as 0.60 

ppm ozone, 2-hr average, as indicated in 40 CFR Part 51.151. EPA believes that 

the existing ozone-related provisions of 40 CFR Subpart H remain appropriate. 

Therefore, EPA expects that for purposes of the 1997 8-hour ozone NAAQS, 

States need only to confirm that they have existing emergency episode plan 

provisions consistent with EPA's existing regulatory requirements. 

By statute, States are required to make SIP submissions to meet the basic 

requirements of CAA sections l lO(a)(l) and (2) within 3 years after promulgation 

of any new or revised standards. For the 1997 8-hour ozone and PM2.s standards, 

this deadline was July 2000. By Consent Decree, as noted above, EPA has agreed 

to make a determination whether or not States have submitted SIPs to meet these 

requirements by a date certain. In the case of 8-hour ozone SIPs, this date is 

December 15, 2007. For PM2.s SIPs, this date is October 15, 2008. In order for 

EPA to evaluate the submissions adequately, EPA requests that States make their 

certifications of SIP adequacy or SIP revisions as soon as possible and to the 

extent feasible sufficiently in advance of these dates to allow EPA time to 

determine whether complete submissions have been made. 

If you have any questions concerning this guidance, please contact 

Mr. David Sanders at (919) 541-3356. Please ensure that the appropriate air 

agency officials for States in your Region are made aware of this guidance. 

Attachments 

cc: Margo Oge, OT AQ 

Steve Page, OAQPS 

Brian McLean, OAP 

Richard Wayland, OAQPS 

Lydia Wegman, OAQPS 

Peter Tsirigotis, OAQPS 

5 
Attachment A: Required Section 110 SIP Elements 

The SIP elements listed below are required under section 1 IO(a)(l) and 

(2). Section 1 IO(a)(l) provides the procedural and timing requirements for SIPs. 

Section 110( a)(2) lists the basic or "infrastructure" elements that all SIPs must 

contain. We note that this list is not intended to constitute an interpretation of 

these provisions, or a change of past practice with respect to these provisions, 

merely a brief description of the required SIP elements. 

Emission limits and other control measures: Section 110(a)(2)(A) requires 

SIPs to include enforceable emission limits and other control measures, means or 

techniques, schedules for compliance and other related matters. EPA notes that 

the specific nonattainment area plan requirements of section 110( a)(2)(1) are 

subject to the timing requirement of section 172, not the timing requirement of 

section 1 IO(a)(l), and also that SIPs to meet this section are not covered by the 

Consent Decree. 

Ambient air quality monitoring/data system: Section 1 IO(a)(2)(B) requires 

SIPs to include provisions to provide for establishment and operation of ambient 

air quality monitors, collecting and analyzing ambient air quality data, and making 

these data available to EPA upon request. 

Program for enforcement of control measures: Section 110( a)(2)(C) requires 

States to include a program providing for enforcement of all SIP measures and the 

regulation of construction of new or modified stationary sources to meet 

prevention of significant deterioration (PSD) and nonattainment NSR 

requirements. 

Interstate transport: Section 110(a)(2)(D) requires SIPs to include provisions 

prohibiting any source or' other type of emissions activity in one State from 

contributing significantly to nonattainment, or interfering with maintenance, of the 

NAAQs in another State, or from interfering with measures required to prevent 

significant deterioration of air quality or to protect visibility in another State. 

EPA has already issued CAIR to assist States in developing SIPs to meet this 

requirement for purposes of the 8-hour Ozone and PM2.s NAAQS, and has issued 

separate guidance to all States on how to comply with each prong of this statutory 

provision. 

Adequate resources: Section 1 IO(a)(2)(E) requires States to provide for 

adequate personnel, funding, and legal authority under State law to carry out its 

SIP, and related issues. 

Stationary source monitoring system: Section l 10(a)(2)(F) requires States to 

establish a system to monitor emissions from stationary sources and to submit 
periodic emissions reports. 

Emergency power: Section 11 O(a)(2)(G) requires States to provide for authority 

to address activities causing imminent and substantial endangerment to public 

health, including contingency plans to implement the emergency episode 

provisions in their SIPs. 

Future SIP revisions: Section 110( a)(2)(H) requires States to have the authority 

to revise their SIPs in response to changes in the NAAQS, availability of 

improved methods for attaining the NAAQS, or in response to an EPA finding 

that the SIP is substantially inadequate. 

Consultation with government officials: Section 11 O(a)(2)(J) requires States to 

provide a process for consultation with local governments and Federal Land 

Managers carrying out NAAQS implementation requirements pursuant to section 

121 relating to consultation. 

Public notification: Section 11 O(a)(2)(J) further requires States to notify the 

public ifNAAQS are exceeded in an area and to enhance public awareness of 

measures that can be taken to prevent exceedances. 

PSD and visibility protection: Section 110( a)(2)(J) also requires States to meet 

applicable requirements of part C related to prevention of significant deterioration 

and visibility protection. 

Air quality modeling/data: Section l 10(a)(2)(K) requires that SIPs provide for 

performing air quality modeling for predicting effects on air quality of emissions 

from any NAAQS pollutant and submission of such data to EPA upon request. 

Permitting fees: Section l 10(a)(2)(L) requires SIPs to require each major 

stationary source to pay permitting fees to cover the cost of reviewing, approving, 

implementing and enforcing a permit. 

Consultation/participation by affected local entities: Section l 10(a)(2)(M) 

requires States to provide for consultation and participation in SIP development 

by local political subdivisions affected by the SIP. 

2